Ultrasonic transducers are used for a variety of applications which require different characteristics. For example, for abdominal imaging, high penetration is required. Therefore a 31/2 MHz tranducer is a good choice. However, for more superfical imaging which is used where only up to 12 cm of penetration is required a 5 MHz transducer is a better choice.
It is well known in the prior art to use more than one transducer in a probe to cover a wide range of applications. In prior art systems, a plurality of transducers are mounted about a common axis and are continuously rotated past an ultrasound window to obtain the scanned data.
When two different transducers are mounted on such a rotating cylinder then the use of one of them at a time for imaging reduces the possible frame rate by a factor of 2. If three different transducers are mounted for rotation on the cylinder then the frame rate is reduced by a factor of three. Since high frame rates enable high quality dynamic imaging by the ultrasound system, it is a goal of experts in the field to provide more than one transducer in a single probe without reducing the frame rate.
Accordingly, an object of the present invention is to provide hand-held ultrasound probes having more than one transducer wherein means are provided so that imaging with the selected one of the multiple transducers is done at the same frame rate as with a probe having a single transducer.